OF SOUTH CAROLINA. 173 
Conwayboro’, where a thin band occurs over the cretaceous formation. On the opposite side of the 
river, higher up, at Porter’s Landing, and at Harper’s, it occurs in a bed twelve feet thick. ‘The 
lower portion is indurated and the fossils not numerous; but I found here Pecten eboreus, very large, 
Pholadomya abrupta,and Conus diluvianus. In the upper portion of the bed, which is composed 
of comminuted shells and Ostrea Virginiana, (the long variety,) the valves of the greater part of 
the shells are displaced, yet Panopea reflexa is frequently found buried in the marl, in the vertical 
position in which it lived and died—showing that these beds have not been disturbed since the 
time of their deposition. The superincumbent bed, at this place, consists of loose yellow sand, 
which constitutes the pine-woods land of this region. 
The position of the beds in this section, which is over a mile in length, will appear from the fol- 
lowing diagram. 
I A OPOPPPPPIVPPPAALG 
30 to40 | Yellow sand, showing false stratification, and very undulating 
; feet. on the surface. 
= _ : =e 
3 6 to 12 Yellow Pliocene marl. ; 
feet. 7 rit : $ 
’ 8 feet. Beds of the Cretaceous formation. 
The next locality, ascending the river, is at Waller’s. Here the marl rests upon the cretaceous 
rocks, which rise above the water only two feet. When I first saw this bed, with its numerous 
valves of the common long oySter of the mud flats of the southern coast, scattered through it 
towards the top, [ supposed I had discovered a P. Pliocene deposit; but a little search corrected 
this impression, for I soon found Venus Alveata, V. cribraria, Pectunculus subovatus, P. 5-rugatus, 
and other characteristic fossils. 
A short distance from this, one of the most interesting localities on the river occurs, on Tilly’s 
Lake, at Nixon’s. The mass of the bed at this place is made up of broken and comminuted shells, 
enclosing multitudes of beautifully preserved fossil shells. Pyrula carica and Arca lienosa, of 
immense size, are found at this place. I found projecting from the middle of the bed, a fragment 
of the jaw of Calorhynchus. 
To the Geologist, examining the Tertiary formation of the South, it is of great importance to visit 
the localities where excavations are in progress ; for the fossils are so destructible that they soon 
crumble, on exposure, in such a manner that a highly fossilliferous bed may present, on the surface 
of a natural section, little indication of the existence of the organic remains enclosed in the mass. 
Some marl had been excavated for economical purposes, a short time before my visit: so that I had 
an excellent opportunity for the study of the Waccamaw fossils. The marl is exposed on the 
river bank, for a distance of four hundred yards, and the strata, at the best exposure, stand thus— 
~ nn 
'30 feet. 
é 
Overlying loose sand and clay. 
Marl. 
10 feet. 
2 feet Cretaceous formation, containing 
; Exogyra costata. 
Weta Dee! eh ee 
44 
